Trampolines



3 Sheets-Sheet 1 A. c. GRI-:LLB Er AL TRAMPOLINES T"- V e 'I Lll Feb. 8,1966 A. c. GRELLE ETAL 3,233,895

TRAMPoLINEs Filed Oct. 15, 1961 3 Sheets-Sheet 2 f6 24 J4 v Feb. 8, 1966A. c. GRELLE ETAL 3,233,895

` TRAMPoLINEs Filed Oct. 13, 1961 3 Sheets-Sheet 3 United States PatentO 3,233,895 TRAMPOLINES Albert C. Grelie, Clairton, Pa. (3150 N.Atlantic Ave.,

Apt. 100-7, Cocoa Beach, Flin), and John K. Rauschenberger, 388 CavanDrive, Pittsburgh 36, Pa.

Filed Oct. 13, 1961, Ser. No. 144,948 9 Claims. (Cl. 272-65) Thisinvention relates to trampolines and specifically to a safe, detachableconstruction for a trampoline which can be applied to a singletramopline or to multiple-unit trampoline centers.

The primary object of this invention is the construction of a portableabove-ground tramopline center which eliminated the hazards of injury toa jumper from striking the trampoline frame or from slipping between thesprings and which may be installed satisfactorily on uneven terrain. Y

More specifically, the objects of this invention are:

To construct a trampoline eliminating the tubular trampoline frame andconsequently the injury hazard it presents.

To provide a protective cover for the rebound springs of a trampoline ofsufficient rigidity that it will protect against a person slippingbetween springs but will not interfere with the action ot' the springs.

To provide a rigid protective cover for the rebound springs of atrampoline of sufficient rigidity that it will protect against a personon the trampoline slipping between adjacent'springs but which willpresent a resilient shock absorbing surface to prevent injury to ajumper falling on to the spring area or edge of the trampoline.

To provide a rigid protective cover which can be used on framelesstrampolines or on trampolines having a frame to prevent injury tojumpers falling on to the spring and -frame area.

To construct a portable trampoline center employing a minimum ofdifferent elements in its construction.

To provide braces or supports for the elevated deck of a tramp-olinecenter which supports are constructed of a minimum of dierent elementsand can be erected to levelly support the deck over uneven terrainsloping in one or more directions.

' These and other objects and the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

FIGURE 1 is a plan View illustrating the general layout of a multipleunit trampoline center constructed in accordance with this invention.

FIGURE 2 is a more detailed view of a single trampoline unitillustrating the attachment of the rebound springs and the location andmanner of attachment of the spring covers.

FIGURE 3 is a sectional View along the line 3-3 in FIGURE 2 showing indetail the manner of attaching the rebound springs to the box frame, theconstruction of the spring cover and the mode of attaching it to thesprings.

FIGURES 3a, 3b and 3c are views similar to FIGURE 3 but showingdifferent modes of attaching the rebound springs to alternativestructures of the box frame. FIG- URES 3a and 3b also show alternativemeans of attaching the spring cover to the rebound springs.

3,235 Patented Feb. 8, 1966 ICC FIGURE 4 is a sectional View through acushion or bumper block for the spring covers taken along the line 4-4in FIGURE 2.

FIGURE 5 is a perspective View of a retaining block which can be used toattach the spring cover to the springs.

FIGURE 6 is a perspective view of a supporting brace for the elevatedplatform having two supporting arms which can be adjusted to permit theplatform to be supported at a level attitude on uneven terrain.

FIGURE 7 is a perspective view of a supporting brace similar to that inFIGURE 6 except that it has three supporting arms.

FIGURE 8 is a perspective View of a supporting brace similar to thatshown in FIGURE 6 except that it has four supporting arms.

FIGURE 9 shows an alternative -form of supporting brace.

FIGURE l0 shows the spring cover of this invention applied to atrampoline having a tubular frame.

Referring more specifically now to the drawings it will be seen that thenumeral 10 refers to the rebound bed of a trampoline. The rebound bed isusually made of a woven material either in one piece or of interlacedwebbing. In some cases it is made of perforated sheet material. Thematerial most commonly used is nylon. However, the nature of the bedforms no part of this invention and is recited here merely forinformation. The bed has a series of loops 11 located around itsperiphery and suitable to receive one end of a rebound spring 12. In thepreferred embodiment of this invention the other end of each spring ishooked through apertures 13 in one leg 14 of an angular spring retainingstrip 15 secured to the members 16 of a box frame 17.

Alternatively as shown in FIGURES 3a and 3b the members of the box frame17 may be made of met-al or a rigid plastic of angular or I-beam crosssection and provided with spring receiving apertures 18 or other meansfor attaching the ends of the springs such as the eye bolts 19 securedin apertures 20.

FIGURE 3c shows another alternative construction in which one end of therebound springs 12 is secured to a rod or tubular bar 63 maintained in aposition slightly spaced from the box frame members by bolt, nut andwasher assemblies 64, 65, 66. The Shanks of bolts 64 t loosely in bores67 in the box frame members so they are relatively free to followvertical and lateral movements of the rod or bar 63 as the springs'aredeflected under load of a person jumping on the trampoline. Thus only atensile load is applied to the bolts.

As seen in FIGURE l a typical above ground trarnpoline center mayconsist of a number of trampolines indicated generally by the numeral 26set into a platform or deck 27. In the form covered by this inventioneach trampoline is entirely within its box frame. Deck plates 25 are seton top of and secured to the frame members between adjacent sides ofeach trampoline to provide a walkway or butter area. Extensions 29 oftheframe members serve to tie the trampolines together and provide anintegral platform above the ground. An outer frame 31 completes theplatform and together with extensions 30 provides support for Aan outerwalkway 32. The peripheral area between the edge of each rebound bed andthe adjacent edge of the deck is covered by substantially rigid springcovers 24.

It can readily beseen that-inl the form of this invention there ispresented a continuous substantially smooth and level surface over theentire area of the platform. All of this surface is capable ofsupporting the Weight of a person Walking on it. In addition the springcovers 24 have a resilient, shock absorbing top layer 33 to protect ajumper from injury if he falls olf the rebound bed onto the spring orframe area While performing on the trampoline. The spring covers arepreferably made of two-layersr33 and 34; The bottom layer 34 ispreferably of wood or some other material havingl sufficient rigidity tosupport the weight of a person stepping on the spring area. The toplayer 33 may be of foam rubber or plastic foam material. In practice anexpanded polyurethane foam is preferred because it appears to retain itsresilience and is relatively unaffected by exposure to weather andmoisture and does notretain water. However., any rubber or plasticmaterial or any other substance having the requisite resilience andshock absorbing characteristics may be used. Foam rubber has a tendencyto deteriorate in the presence of heat and moisture and retains water.Therefore, if it or certain other substances are used it is necessary toprotect the spring cover. with a non-porous, water-repellent sheetmaterial. The spring covers may be made long enough to cover .all of thesprings on one edge ofthe rebound bed or to facilitate handling andconstruction, they may be made shorter than the lengthofa side of therebound bed and two or more used at each side. Suitable provision suchas mitering is made so the spring covers meet and match at the corners.

T-he spring cover is'made to followthe vertical deflection of theSprings during use of the trampoline by means of retaining blocks 35shown in detail in FIGURE 5. A` series of cushion or bumper blocks 36which may be of the same material as the top layer 33 of the springcover help to resiliently support the spring cover on the springs. Asound deadening member 37 may be placed inside each spring contacted bya retaining block to dampen vibrations caused by rubbing contact betweenthe spring and the block and reduce noise.

The retaining blocks are provided with a Ipair of parallel grooves 33 ofgenerally cylindrical shape, the diameter of the grooves being slightlylarger than the outside diameter of the rebound springs. The distanceacross the 'block between adjacent edges of grooves being slightly lessthan the spacing between adjacent springs,

on which the block will ride. In this manner there is no interferencewith the action of the springs. The grooves 3S may be so proportionedthat the springs must be inserted axially therethrough rather thanthrough the side opening.

In the preferred construction the spring retaining member 15 may be anangle iron of suitable size and strength and may be attached to theframe members by bolts and nuts 21 or by lag screws. The retainingmembers 15 are attached. to the box frame members 16 at a pointsuciently below the level of the top 22 of the frame members that thetop surface 23 of the spring cover will be substantially flush with thetop surface of the deck plates 25 when the whole is assembled.

A block 39 may -be attached along the lower edge of the spring cover sothat it rests on the spring retaining member 15 and helps support thespring cover and maintain it in position.

Alternatively as shown in FIGURES 3a and 3b tne retaining blocks 35 maybe dispensed with and replaced with additoinal bumpers 36. Attachment,between the spring covers and the springs may be by means of elasticattaching strips 4t) as shown in FIGURE 3a'. The attaching strips may belooped through the hooks on the ends of the springs and the ends of theloop secured by suitable fasteners 41 to the spring cover.

The spring cover may also be held in position on the springs as shown inFIGURE' 3b"by a releasable clasp 42 .attached to the xed endofthe springand` to a fastener 43 such as a screw eye on the underside of the springcover. An elastic cord 44 attached to the other end of the spring .bymeans of a releasable clasp 45 and connected to the underside of thespring cover yby a fastener 46 causes the spring cover to follow thespring and the edge of the rebound bed. Thus a continuous supportingsurface is always presented to a jumper on the trampoline from the edgeof the rebound bed to the deck area.

Each box frame is supported.' from the ground near its corners and atintervals along the length of its members as requiredv to` givesufficient: rigidity to the box same basic elements are used inconstructingeither thevv two, three or. four arm braces.

Each of the braces consists of a base 48 and an upright member 49.resting in a groove 50 in the base. The upright member. is relativelyfree to move longitudinally in the groove 50. A pair of angular brackets51 and 52 are attached to the center of the upright member by means of abolt and nut 53A orf other suitable fastening means extending throughthe upright member and one leg 54, 55 of. each bracket. The other leg56, 57 o'f each bracket extends generally at right anglesl to itsrespective one leg. Links or arms 60 and 61 are attached to legs 56 and57 respectively ofthe bracket by nut and bolt assemblies 58 and 59 orother suitable fastening means. The other end of eachy link is securedto the member. 62 to be supported by means of bolt and nut assemblies 63and 64. The member 62 represents either a box frame member or a decksupporting member.

It can readily be seen that the location of bolts 5S and 59 can beadjusted so that the member 62 is supported at a level attitude by thelinks,v 60 and 61 even though the terrain on which the base 148 rests`may be inclined. To compensate for. slope of the supporting terrain in adirection along the longitudinal axisof the upright member 49, brackets51 and 52 canbe swivelled about the bolt S3 until the arms 60, 61 areparallel to member 62.

Preferably, but not necessarily, brackets 51 and 52 `are located so thattheir link supporting arms are offset from each other approximately thethickness of member 62. The links 60, 61- canthus be attached toopposite sides of member 62 to lendadditional. rigidity to thestructure.

At. places in the platform structurevwhere the frame members form a T,as fory example at the junction of extensions 30 with the outer frame 31of the platform, a supporting brace .having three supporting arms asshown in FIGURE 7 may beprovided. For this structure an additional linkor arm 70 is inserted between one of the brackets 51 or 52 and theupright member 49. The arm 70 is secured to the member 49 by thesamebolt and nut assembly 53, 54 as is used'to'attach the brackets.

As seen in FIGURE 8 the braces with four supporting arms are constructedby insertingv a fourth ar-m 71 under the bracket 51 or 52 on theopposite side -ofmember 49. Braces with four supporting armsmay beprovided at the corners of the box frames. It is obvious ofcourse thatall the support bracesy may be of the type having two;

supporting arms or that they may be used in any suitable.

combination With braces having three or four supporting arms.

FIGURE l9 shows another form of support brace. This bolt receivingapertures spaced about its periphery is threaded onto the support bar.Two, three or four supporting arms or links 78, as required may bepivotally attached to the sleeve 76 by bolt and nut assemblies 79 orother suitable fastening means passing through bolt receiving aperturesnear the ends of the supporting arms 7 8 and the trunnions 77. The otherend of each supporting arm is provided with an aperture 80 for receivingfastening means for attaching the arm to the member to be supported,such as the frame members 16 and extensions 29 and 30.

In the structure shown in FIGURE 9 the height of the support brace maybe adjusted by rotating the support bar or jack screw 75 as required.This may be necessary to compensate for settling of the ground under asupport brace after initial installation or to simplify installation ofa brace over a pronounced depression without requiring extremeadjustment in the angle between the supporting arms. Vertical adjustmentcan be made without detachment of any parts and while the brace is underload. Polygonal lands 81 or extensions 82 may be provided on the jackscrew to permit application of a wrench.

As shown in FIGURE 10 the spring cover of this invention can be appliedto a conventional trampoline having a tubular frame. FIGURE l0 shows thespring cover attached by retaining blocks 35 but it is apparent that thealternative means described in connection with FIGURES 3a and 3b may beused or suitable means may be employed to attach the spring cover to thetubular frame.

In any of these structures the spring covers may be attachedalternatively or additionally to the deck or box frame by suitablemeans.

Obviously many modifications and variations of this invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What we claim as our invention is:

1. A trampoline comprising a rebound bed secured by a peripheral row ofsprings to a rigid frame and a protective spring cover consisting of aflat substantially rigid sheet member having a resilient shock absorbingtop surface and extending from an edge of the rebound bed over the areaoccupied by the springs attached to said edge.

2. In a trampoline comprising a rectangular rebound bed supported byfour rows of tensioning springs one each of said rows being stretchedbetween one edge of said rebound bed and the adjacent inner periphery ofa box frame surrounding the rebound bed, a spring cover for at least oneof said rows of springs consisting of a flat substantially rigid memberhaving a resilient shock absorbing top surface and extendingsubstantially from the edge of the rebound bed over the area occupied bythe springs.

3. A trampoline comprising a rebound bed secured by a peripheral row ofsprings to a rigid frame and a protective spring cover supported solely'by the springs and secured solely thereto said cover extendingsubstantially over the entire area occupied by the springs and beingsufciently rigid t0 support the weight of a person jumping thereon toprevent the foot of a person landing on the area occupied by the springsfrom slipping between adjacent springs.

4. A trampoline center comprising a platform structure having aplurality of rigid frames arranged in parallel rows and connected byframe extensions to form a deck area to receive a plurality of rows oftrampolines, said frame extensions supporting walkways separating saidrows of trampolines and additional frame extensions supporting an outerwalkway around the periphery of said platform structure, each trampolinecomprising a rebound bed secured by a peripheral row of springs to oneof said rigid frames, the level of the rebound bed being slightly belowthe level of the top surface of the walkways, and a protective springcover for each trampoline, said spring cover lbeing of substantialthickness and lresting on the springs, the top surface of the springcover being substantially Hush with the top surface of the walkways andsaid spring cover overlying the area between the edges of the reboundbed and the contiguous edges of the walkways so that a substantiallysmooth continuous surface is provided over the entire area of thetrampoline center.

5. A trampoline center comprising a platform structure having aplurality of rigid rectangular frames arranged in parallel rows andconnected by frame extensions to form a deck area to receive a pluralityof rows of trampolines, said frame `extensions supporting walkwayseparating said nows yof trampolines and ladditional frame extensionssupponti-ng an outer walkway around the periphery of said platformstructure; each trampoline oomprising -a rebound bed secured by aperipheral row of springs Ito one of said rigid Irectangular frames, thelevel of the :rebound bed being slightly below the llevel of the lto-psurface of the walkways; and a substantial-ly rigid protective Vspringcover for teach trampoline resting on said springs, said spring coverbeing of substantial thi-ckness and having a resilient, shock 'absorbingtop surface, fthe top sur-face of `the .spring cover being substantiallyllush with the top surface of the walkways when the tramp-oline is notin use and said spring cover overlying the area Ibetween .the edges ofthe rebound bed and the contiguous edges of the walkways.

6. A trampoline center comprising a decklike structure including aseries of trampolines arranged in parallel rows separated by walkwaysand surrounded by an outer walkway, each trampoline comprising a reboundbed secured by a peripheral row of springs to a rigid frame, aprotective cover over the springs secured solely to said springs, saidcover consisting of a flat substantially rigid sheet member having aresilient shock absorbing top surface and extending from an edge of therebound bed over the area occupied by the springs attached to said edge,and a plurality of supports for said decklike structure to hold it inelevated position above the ground.

7. A trampoline center comprising a decklike structure including aseries of trampolines arranged in parallel rows separated by walkwaysand surrounded 'by an outer walkway; each trampoline comprising arebound 'bed secured by a peripheral row of springs to a rigidrectangular frame, the level of the rebound bed being slightly below thelevel of the top surface of the walkways; a substantially rigidprotective spring cover for each trampoline resting on said springs,said spring cover being of substantial thickness and having a resilient,shock absorbing top surface, the top surface of the spring cover beingsubstantially flush with the top surface of the walkways when thetrampoline is not in use and said spring cover overlying the areabetween the edges of the rebound bed and the contiguous edges of thewalkways; and a plurality of similar supports to maintain said decklikestructure in a level position elevated above the supporting terrain.

8. A trampoline center comprising a decklike structure including aseries of trampolines arranged in parallel rows separated by walkwaysand surrounded by an outer walkway; each trampoline comprising a reboundbed secured by a peripheral row of springs to a rigid rectangular frame,the level of the rebound bed being slightly below the level of the topsurface of the walkways; a substantially rigid protective spring coverfor each trampoline resting on said springs, said spring cover being ofsubstantial thickness and having a resilient, shock absorbing topsurface, the top surface of the spring cover being substantially flushwith the top surface of the walkways when the trampoline is not in useand said spring cover overlying the area between the edges -of therebound bed and the contiguous edges of the walkways; and a plurality ofsupports to maintain said deckline structure in a level positionelevated above the supporting terrain, each of said supports comprisinga base member, an opstanding member resting on said base andextending ina generally vertical position from said base and at least two supportlinks pivotally supported from said upstanding member and extendingdiagonally in avgenerally upward direction to- Ward the structure to besupported.

9. A platform structure comprising a peripheral horizontal deck area inthe shape of a closed rectangle supported above the ground lby a decksupporting structure including a box frame defining the inner boundaryof said deck area and forming an integral part of the deck supportingstructure, a trampoline surrounded by said deck and comprising a reboundbed supported at its edges by springs attached to the members of saidbox frame.

Reerenees Jited 'by the Examiner UNTTED 3/1945 9/1949` 5/1951 3/19527/196'1 l0/-l96l S/1962 STATES PATENTS Nissen v 272-65 X Isakson 24S-194 Bloch 248-194 Hendershott 272-1 Sampson 1812-139 Nissen 182-139Mikesell 182-139 RCHARD C. PNKHAM, Primary Examiner.

GEORGE H. BREHM, Examiner.

9. A PLATFORM STRUCTURE COMPRISING A PERIPHERAL HORIZONTAL DECK AREA INTHE SHAPE OF A CLOSED RECTANGLE SUPPORTED ABOVE THE GROUND BY A DECKSUPPORTING STRUCTURE INCLUDING A BOX FRAME DEFINING THE INNER BOUNDARYOF SAID DECK AREA AND FORMING AN INTEGRAL PART OF THE DECK SUPPORTINGSTRUCTURE, A TRAMPOLINE SURROUNDED BY SAID DECK AND COMPRISING A REBOUNDBED SUPPORTED AT ITS EDGES BY SPRINGS ATTACHED TO THE MEMBERS OF SAIDBOX FRAME.